Author

Topic: One more BFL Asic board for fun and free design (Read 607 times)

full member
Activity: 128
Merit: 100
September 25, 2013, 09:20:17 PM
#1
Cheers,

I try to make my own pcb :-) Details will follow but here the first facts:

  • Main PCB will get µATX, ATX or E-ATX form factor
  • Main PSR is default ATX PSR mounted in 19" server rack which the main pcb will be mounted
  • BFL Chips will be solder on carrier PCB in one of actual CPU Socket form factor (e.g. LGA1155). They will get an copper heat spread on top mounted.
  • Every Carrier can handle one to max 7 chips (maybe 8 depends on needed adress for PSRs)
  • On Main PCB CPU sockets will be mounted to connect the BFL carrier and a proper CPU cooler solution
  • Every BFL will get there own (maybe programmable) psr (which needs one own SPI address for psr controller) with sense lines as near as possible to the chips
  • Option for external clock is planned (maybe need one more SPI address).
  • BFL Chip Controller solution is selectable: AVR or Rasberry Pi (or other)
  • Temperature will be measure by internal chip temp sensor
  • KiCad will be used for planning the layout and design.
  • The design files will be shared.

Ready:
  • Documentation from BFL stored
  • BFL Chips ordered and fully payed
  • KiCad installed.
  • BFL Chip symbol created for KiCad

Next Steps:
  • Generate simple layout for carrier pcb
  • Generate simple layout for main pcb
  • Create chips to socket netlist
  • Select psr module solution

Open questions:
  • Documentation from BFL described Done signals in daisy chain mode. On SC Board instead chip done signals are directly connected to AVR. Why?
  • What are the possible heat spread sizes for different LGA sockets? In fact also what are the dimensions of different cpu's?
  • How much CPU sockets can be used on main pbc?
  • Maybe because of large size 2 Layer board could be used for main pcb.
  • Is the Rasberry Pi strong enough?
  • When will I get my BFL chip order in hand? In 1st week of october as promised?
  • How much are the costs of the more expensive parts?

My recent favorites:
  • 8 BFL on LPGA-2011 Carrier with copper heat spread because of needed min. die size 42mm x 42 mm
  • 8 PowerOne DP8120 POL controlled by DM7308 Power controller
  • Rasberry Pi as Controlller with SPI Mode for controlling BFL Chips
  • Fallback PSR DeltaOne D12S050201C with trim

References:

To be continued.
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